Magazine article American Scientist

Detecting Single Molecules to Improve Disease Diagnostics

Magazine article American Scientist

Detecting Single Molecules to Improve Disease Diagnostics

Article excerpt

For this installment of the Meet Your Fellow Companion series, Sigma Xi's manager of communications, Heather Thorstensen, spoke with member Dhruvajyoti Roy, a senior scientist at Nanogea Corporation in Culver City, California. He is on a team that is developing technology for biomedical applications. One way this technology could be used is to improve the process for diagnosing illnesses such as cancer and Alzheimer's disease.

The technology that you're developing can be used to diagnose diseases by detecting biomarkers. Could you explain what a biomarker is?

A biomarker is a measurable indicator of some biological state or disease condition. An ideal biomarker has certain characteristics that make it appropriate for checking the severity of a particular disease or a particular disease state.

How will the technology that you're developing find these biomarkers?

We are focusing on commercializing the industry's most sensitive single molecule detection platform based on our company's proprietary NanoCone(TM) chemistry and NanoCone Enabled Atomic Force Microscopy (NE-AFM(TM)). In the case of protein biomarkers, our approach combines two key features: the specificity determined by a probe antibody on the microarray platform and the label-free AFM (atomic force microscopy) readout.

Let me explain briefly how the technology works. Typically, to detect a target protein biomarker, a matched pair of antibodies is selected. One of these antibodies is known as the capture antibody and it is spotted on a substrate with a conventional microarray spotter. This is a spatial array of microscopic spots of biological material attached to a solid surface. The other antibody is the detection antibody and it is immobilized on an AFM probe. The capture antibody on a microarray platform specifically captures the target biomarker present in a biological sample from a patient. After capturing, the substrate is washed and then we do a cross-linking step to secure the biomarker on the antibody spot. At this point, the substrate is ready to scan. We employ a forcebased AFM approach to detect the captured biomarker directly where the controlled surface architecture allows a single molecular interaction between the detection antibody on an AFM tip and the target biomarker on a substrate. The highresolution force-based mapping capability of AFM enables us to "see ahd count" them in a sub-micrometer designated area. The technology can also be utilized for other forms of biomarkers such as DNA, RNA, and small molecules.

How would this technology be used if commercialized?

The early and accurate detection of the presence of certain biomarkers would enable physicians to diagnose cancer and other diseases much earlier. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.